The present invention relates to a cleaning apparatus for cleaning the ink rollers of a rotary printing press.
In the rotary printing press, when the printing operation is ended or when the color of an ink in the ink fountain is to be changed, the ink in the ink fountain is discharged and an ink roller cleaning operation is performed to clean off the ink attaching to the circumferential surfaces of the respective rollers of an ink ductor roller group so as not to affect the next printing operation.
In this cleaning apparatus, a cleaning solution is sprayed to the upstream ink roller of the ink roller group, and the cleaning solution and the waste ink transferred to the downstream ink roller are scraped with a cleaning blade abutting against the circumferential surfaces of the ink rollers to drop into a cleaning solution tank. With this arrangement, every time the circumferential surfaces of the ink rollers are cleaned, the ink attaching to the distal end of the cleaning blade and to the cleaning solution tank must be cleaned, leading to a burden on the person in charge of the cleaning operation.
As a cleaning apparatus which reduces the burden on the person in charge of the cleaning operation, one in which the waste ink scraped with the cleaning blade is collected with a cleaning cloth is proposed. Japanese Patent Laid-Open No. 6-262757 (Reference 1) discloses a cleaning device in which the waste ink on the circumferential surface of the ink roller is wiped off with a cleaning cloth urged against the circumferential surface of the ink roller through a pad, and the cleaning cloth is also urged against the cleaning blade urged against the circumferential surface of the ink roller, so that the waste ink scraped with the cleaning blade is collected by the cleaning cloth.
U.S. Pat. No. 5,168,812 (Reference 2) discloses a cleaning apparatus in which the waste ink on the circumferential surface of the ink roller is scraped with a cleaning blade, and the cleaning blade can come into contact with and separate from the circumferential surface of the ink roller. When it is separated, the cleaning blade is abutted against a cleaning cloth that awaits on the rear surface side of the cleaning blade, thereby collecting the waste ink.
With the device of Reference 1 described above, since the cleaning cloth is strongly urged against the circumferential surface of the ink roller, the cleaning cloth tends to be torn apart by the ink roller rotating at a high speed during cleaning. In order to prevent this, an expensive special cleaning cloth having high durability must be used. Because of the viscosity of the waste ink wiped by the cleaning cloth, the cleaning cloth is pulled and caught by the circumferential surface of the ink roller, causing a cleaning trouble.
With the apparatus of Reference 2, since the cleaning blade is intermittently separated from the circumferential surface of the ink roller during cleaning, the time period while the cleaning blade is separate results in a time loss, additionally prolonging the cleaning time.